Pictures and in depth explanation of the mechanical why’s and wherefore’s will be presented.
Had several conversations with TOC today, who has had more in-depth mechanical “insight” with this loco than anyone else I know…
Back to work…
Greg
Bart Salmons said:
Ummmm all my switches are hand laid…
Bart
We found that the pilot would tend to pick even the slightest bump between track sections and at points. Each year In the spring, we run a K with an original pilot to find a whole host of small track problems. Slight grinding with a Dremel at these locations provides a very noticeable improvement.
To improve the pilot tracking. we ended up putting a larger spring in the pilot to increase the pressure against the rails and improving the wheel profile. Both changes significantly reduced derailments. All Bachmann locomotives post the K have a much improved wheel profile.
Greg Elmassian said:
Pictures and in depth explanation of the mechanical why’s and wherefore’s will be presented.
Had several conversations with TOC today, who has had more in-depth mechanical “insight” with this loco than anyone else I know…
Back to work…
Greg
Greg
Dave has a lot of knowledge and talent. A site with photos would be a great addition and help to those that wish to tinker with their K. Hopefully you can use this opportunity to also correct the mistakes on the current site.
Stan
My personal experience with the K was that the pilot and #1 axle would constantly derail at any given place but especially after turns. It also liked to pick switches. I run USA #6, aristo wide radius and my own #5 switches. It hated the aristo switches which is another story.
So, I removed the pilot and the #1 axle would still derail. Put the pilot back on. Setting the loco on a flat table you could visibly see that it had butt sag, bad. The rear springs were almost fully compressed the front springs were almost fully extended. I found this by just pushing down on the loco. I also found that #3 driver (with the motor) would jam in the slide housing adding to butt sag. Next I realized that the axle centering springs on my loco were too weak to center the loco back on the track so after coming out of a curve the loco would point off to the side. Now, put the two together, heavy to the rear and unable to center itself obviously #1 driver & pilot are going to derail. Add to all that pulling a dozen AMS cars and you could actually see #1 driver coming off the rail head like the loco was trying to do a wheelie. (cool if it was a hot rod)
I do have Rodney’s gear reduction on the loco which I think added a little to the butt sag and may not help with #3 axle sticking. BUT, even before the modification the loco had the same exact tracking and derailing problems.
So, I repaired my problems. I added stronger springs to the back, fixed the #3 axle from sticking and added a spring above the gearbox to assist in keeping #3 down and locked #1 & #4 axle in place. I now have zero problems. I have to admit though that I may have stiffened up #3 axle too much, spring running will tell.
Terry